Autor M. K. Mohamed, A. M. Samy, W. Y. Ali
Infos zum Autor Mohamed M. K.*, Samy A. M.*, Ali W. Y.**

*Faculty of Engineering, El-Minia University, El-Minia, EGYPT.

E-mail m.mohamed2000@yahoo.com
**Faculty of Engineering, Taif University, Al-Taif, Saudi Arabia.
E-mail wahyos@hotmail.com
Inhalt Abstract

The present work discusses the effect of the treads width and depth of the shoe sole on the friction coefficient between the shoe and ceramic floor interface. The friction coefficient between the rubber test specimens of treads of different width and height, and the tested ceramic flooring tiles, was measured by using a test rig designed and manufactured for this purpose. Rubber test specimens were loaded against dry, water and water/detergent mixture, oil and oil/water dilution lubricated flooring tiles. Based on the experimental results of the present work, it was found that, at dry sliding, friction coefficient slightly increased with increasing treads height. Perpendicular treads displayed the highest friction coefficient due to their increased deformation, while parallel treads showed the lowest values. In the presence of water on the sliding surface significant decrease in friction coefficient was observed compared to the dry sliding. For detergent wetted surfaces, friction coefficient drastically decreased to values lower than that displayed by water. Parallel treads showed the highest friction coefficient, while perpendicular treads displayed the lowest friction values as a result of the formation of the hydrodynamic wedge. Oily smooth surfaces gave the lowest friction value as a result of the presence of squeeze oil film separating rubber and ceramic. Treads of 45° displayed the highest friction coefficient. Emulsion of water and oil shows slight friction increase compared to oil lubricated sliding. As the tread height increased friction increased due to the easy escape of the lubricant from the contact area. Besides, friction coefficient significantly increased up to maximum then slightly decreased with increasing the treads height. Perpendicular treads displayed the highest friction followed by 45° and parallel treads. At water, detergent and oil lubricated sliding conditions, friction coefficient decreased as the tread width increased due to the increased area of the fluid film. Smooth surfaces gave the lowest friction values as a result of the presence of squeeze oil film separating rubber test specimens and ceramic tiles. The friction decrease may be due to the increased ability of the tread to form hydrodynamic wedge as the tread width increased. Perpendicular treads caused lower friction coefficient because parallel and 45° treads could scavenge oil away from the contact area more effectively than perpendicular treads.
Datum 2010